The present invention relates to a lamp unit used as a light source for copying machines, facsimiles or other equipment.
Conventional light sources for copying machines include, for example, a combination of straight fluorescent lamps. Generally, fluorescent lamps comprise a bulb, a pair of bases fixed to either end of the bulb, and a pair of base pins protruding from each base. The lamps are placed in the housing of the copying machine so that their base pins fit into sockets in the housing. In a copying machine, an aparture-type or reflection-type fluorescent lamp are utilized, which are provided with an elongate radiation window which extends throughout the axial length of the lamp and through which visible light beams are emitted.
Since the interior of the copying machine is very narrow, however, the lamps cannot easily be replaced. The fluorescent lamps are arranged so that light beams radiated from the respective radiation windows of the lamps are converged on a single line. When locating the lamps by fitting their base pins into the sockets in the machine housing, it is difficult to mount the lamps accurately in position, and a fine adjustment of the mounting position of each individual lamp is impossible, owing to play between the pins and sockets. Accordingly, the light beams emitted from the fluorescent lamps cannot easily be converged on a desired straight line, lowering the operating efficiency of the copying machine. Furthermore, the lamps must be individually replaced and positioned, which is time-consuming in terms of maintenance.